Tamoxifen Users on Estring?

I was on AIs, not tamox, so it's not exactly the same thing.  But I use an estring and have since a year or so after active treatment.  My MO explained that she preferred estring to any topical estrogen because estring gives a consistent, but very low dose of estrogen into the vaginal tissues - estrogen creams give you a big dose right when you apply them, then it wanes until you give it the next big dose.  She preferred the consistency of the estring.  When the vaginal tissues are dried, there is more absorption right when you start using the estring, but once the tissues "plump up" and become more normal, then the amount of estrogen absorbed drops a lot.  (Think of painting a new wall - you might use a gallon for that first coat of primer as the walls suck up the paint, but when you put on the first coat of color you'll use three quarters of a gallon, and when you apply the third you'll need only half a gallon to paint the same wall.)

After several months of use, my MO tested my estrodiol levels and they were less than 7 - she said anything less than 10 was great.  

Tamox works differently than AIs work, so my experience may not be as relevant, but I wanted to give you some kind of response, and hope that someone who was on tamox will jump in later.